It is well-known that periodontal disease affects a significant portion of the population. It is also well-established that periodontal disease is primarily caused by complex aggregates of microorganisms, primarily bacteria, in the crevice regions between the teeth and the teeth and the gums. These aggregates are commonly referred to as dental plaque.
While brushing with conventional toothbrushes and flossing are currently the standard methods of removing, disrupting and dispersing dental plaque, such techniques have proven to be at best only partially effective, as indicated by the widespread incidence of periodontal disease in the population.
U.S. Pat. No. 4,787,847 is illustrative of a new development in toothbrushes which shows promise in reducing periodontal disease when used regularly. The device utilizes a transducer to produce vibrations in a brushhead, which results in mild cavitation being produced in the gingival (between teeth and gums) fluids in the mouth. This tends to remove the subgingival plaque and to demobilize motile bacteria therein.
However, the device relies on the presence of saliva and toothpaste foam as the medium through which the acoustical energy is conducted and in which cavitation occurs. For many users of the device, this may not be sufficient, especially for the upper teeth. There is no means included in the device for supplying fluid to assure an adequate medium.
In another line of development, medications are known which are capable of inhibiting or killing bacteria responsible for periodontal disease, and the use of such medications has been promoted to the public for such a purpose. Such medications may be used in toothpaste, mouthwash, or solutions applied to the areas of interest. However, such medications are typically expensive when used on a daily basis, have been found to stain teeth in some cases with prolonged use, and in other cases, such as when they are in a mouthwash, are only marginally effective. Applying medication with brushing is convenient for the user and results in the treated area simultaneously undergoing cleaning and the application of medication. However, medication is typically not carefully applied in controlled amounts during brushing. There currently is no convenient way of assuring the application of only therapeutic amounts, so as to prevent waste of the medication, while still being fully effective.
In still another independent line of development in dentistry relating specifically to toothbrushes and toothpaste, it is known to include structure for dispensing a dentifrice in an otherwise conventional toothbrush. In one approach, the toothbrush includes an attachment which dispenses toothpaste in some manner onto the tips of the bristles. Typically, these devices include a reservoir for storing the dentifrice and a means for pumping out the dentifrice from the reservoir onto the tips of the bristles. Examples of this approach include U.S. Pat. Nos. 4,787,765 and 4,695,177, both to Kuo. In another approach, dentifrice is dispensed to the base of the toothbrush bristles. U.S. Pat. No. 4,221,492 to Boscardin et al is an example of this approach, as is U.S. Pat. No. 4,655,627 to Bradley, which also discloses a self-sealing reservoir.
U.S. Pat. No. 4,039,261 to Evans shows a still further approach, involving hollow bristles, in which the dentifrice is moved into the bristles at the base thereof and then is moved through the bristles under pressure to the tips. However, the bristles are oversize and do not provide the typical brushing action for the teeth. Also, there is no provision of a cap or similar element to prevent leakage and/or drying of the dentifrice.
The above-described dentifrice-dispensing toothbrushes, however, have several disadvantages. They typically include complicated mechanisms for supplying the dentifrice to the brushes, resulting in inconvenient overall size of the toothbrush, high cost, and reliability problems. Those devices which use pastes have the additional problems of clogging and the formation of hard, cake-like deposits, which prevent reliable flow of the paste when needed. None of these devices supply fluid at a controlled rate which is needed to assure a proper acoustical effect for a vibrating toothbrush, as described above. Further, the lack of fluid control makes such devices unsuitable for use as applicators of therapeutic (medication) agents.